Machine for curving and bending metallic sheets of different thickness



Jan. 27, 1959 R. BOLDRIN] 2,870,817 MACHINE FOR CURVING AND BENDINGMETALLIC SHEETS OFDIFFERENT THICKNESS Filed Sept. 50, 1953 BY J W$ MUJ MACHINE FOR CURVING AND BENDIN G METAL LIC SHEETS OF DIFFERENT THICKNESS Boldrini, Milan, Italy Application September 30, 195$,Serial No. 383,346

Claims priority, application Italy March 3, 1953 2 Claims. (Cl. 153-54) The present invention relates to three unsymmetrical cylinder machines adapted for curving and bending metallic sheets. H e i It is known how.in sometypes of metal sheet bending and curving machines formed by three unsymmetrically positioned cylinders or rollers, there is one of the rollers that intervenes in the bending of the sheet, which is not only capable of a rotating motion, but also of a vertical translatory motion, so as to allow to vary the distance between said roller and the main driving one, according to the thickness of the sheet to be curved. Said lower and vertically movable roller is always displaced in an axial direction in respect to the upper roller, and this in order to facilitate the clamping and bending action on the metal sheet. The distance however between the two verticals passing through the axes of said rollers is constant, whatever be the thickness of the sheet it is wanted to bend, and this brings about the inconvenience of leaving an unbent portion, with the resulting disadvantages. On the other side, such distance between the two vertical axeshas to be adequate to the thickness of the metal sheet that can be worked in a given machine and therefore it is excessive, resulting in the above mentioned inconvenience, when working metal sheets of smaller thickness.

It is an object of the present invention an improvement in machines of the above mentioned type, and namely according to same, said lower roller is made movable not only in the vertical direction, but also in the transversal direction, according to the thickness of the metal sheet to be worked, so that the thinner sheets will have to be introduced between the two rollers for a shorter distance than the sheets of higher thickness, thus avoiding the inconvenience of leaving unbent a long zone of the very sheet.

The accompanying drawing illustrates very schematically the arrangement of the rollers for an improved machine according to the invention, and namely:

Fig. 1 is a schematic view of the three rollers of the machine, in the position for introducing the sheets, and wherein there are shown in lines differently traced, the positions of the movable rollers, and in particular of the lower roller which clamps the sheet in three different positions.

Fig. 2 illustrates the same rollers in the position when the bending has already been started, on a thin sheet.

As it is apparent from the drawing, the machine in question comprises three rollers A, B, C, where in rollers A and B are driving rollers, and effect the advancement of the sheets while the roller C is movable so as to control the bending true and proper.

Roller B, which in the machines heretofore in use was only movable in the vertical direction, along the vertical passing through its axis, in the improved machine to the invention is instead movable along the line a-b so that, as the thickness of the sheet L varies, not only will vary the vertical distance between the two centers c and e, but also the horizontal distance of the center 1 e of roller B from the vertical c-d passing through the center of roller A.

In Fig. 1, there. is shown in full lines a sheet L having a thickness intermediate between those of sheets that can be bent with the machine shown. There is instead shown 1. in dash and dot lines M the profile of a sheet of greater thickness, and there is shown in dash lines N a sheet of lower thickness thanL. [With similarly traced lines there are shown the position B and B taken by roller B when itis wanted to bend a sheet of a ,thicknesslike M or a I thickness like N. As it is clearly apparent from the drawing these three positions ofroller B vary not only the, distances between the closest points of the periphery of rollers A and B, but will also vary, as already stated, the

horizontal distances between-the vertical passing through mrthe center e of roller B and the vertical c-d passing through thecenter of roller A, In particular, in the draw ing, said horizontal-distance will assume the value 1, in the case of sheet N, the value '2 in the case of sheet L, and the value 3 in the case of sheet M.

Then, as it is also shown in the drawing, since the forward edge of the sheet to be worked, at the beginning of the very operation, has to be introduced and to come in contact with the nearest points of the peripheries of rollers A and B, it can be seen also from the drawing how the position of the sheet edge will result more or less advanced to the left, looking to Fig. 1, relative to the vertical c--d, according to the sheet thickness, that is, for very thin sheets, the piece of sheet that will initially be at the left of said vertical c--d will be very small, and namely will correspond to the distance 1, while in the case of sheet L, it will correspond to the distance 2, and in the case of sheet M, it will correspond to the distance 3. This arrangement reduces to a minimum, and namely to about one time the sheet thickness the flat unbent zone.

Having positioned the sheet to be worked, betweenroller A and B, and resting on roller C, this last roller will be displaced along the straight line 0- in the direction shown by the arrow, to effect the bending of the sheet, while same is being advanced by rollers A and B.

At the beginning of the operation however, the position of roller C will also be adjusted so as to be adapted to the sheet thickness, and in Fig. 1 there are shown with C and C" the positions of roller C at the start of the operations respectively on a sheet like M or on a sheet like N.

In Fig. 2, roller C is shown in a position already displaced while it efiects the bending of a sheet N.

The supporting arrangements and the controls for displacing roller B may be easily built by any one skilled in the art, and may vary according to needs without therefore departing from the field and scope of the present invention. For example, asshown in Fig. 2, the movable rollers may have bearing support at each'end in a carrier 10 which is actuated by a respective screw 14 for effecting adjustment of respective rollers. The carriers are provided with side keys such as 18 slidable in grooves such as 22 cut into the sides of channels 26, wherein the channels are formed Within arms 30 of the machine frame 36. Such construction is conventional for effecting adjustment of rollers.

What I claim is:

1. A machine for curving and bending metal sheets comprising a pair of feed rollers and a bending roller, one of said feed rollers having a fixed axis, the axes of the other feed roller and the bending roller being parallel to each other and to the axis of the fixed feed roller, the axes of the three rollers being disposed in parallel, triangular array, the axis of the other of said feed rollers being adjustable by translation in a plane substantially at right angles to a plane including the axes of the fixed feed roller and the bending roller, and the axis of the bending roller being adjustable in a plane Paiented Jan. 27, 1959 including its axis and the axis of the fixed feed roller, wherein the bending roller is disposed upstream, with respect to the path of the sheets, of the feed rollers and on the side of the path of the sheets opposite the feed roller having a fixed axis,and wherein said other feed roller is adjustably movable withrespect to said fixed .feed roller so as to increase the distance therebetween to match sheets of increasing thickness while simultaneously moving to an adjusted position in a downstream direction to efiect a fulcrum with respect to said fixed roller against which initial bending of a sheet can be achieved by initial adjusting of said bending roller.

2. A machine for curving and bending metal sheets comprising a pair of feed rollers and a bending roller, one of said feed rollers having a fixed axis, the axes of the other feed roller and the bending roller being 'parallel to each other and to the axis of the fixed feed roller, the axes of the three rollers being disposed in parallel, triangular array, the axis of the other of said feed rollers being adjustable by translation in a plane passing between the peripheries of the bending roller and the fixed axis feed roller, and the axis of the bending roller being adjustable in a plane including its axis and the axis of the fixed feed roller, wherein the bending roller is disposed upstream, with respect to the path of the sheets, of the feed rollers and on the side of the path of the sheets opposite the feed roller having a fixed axis, and wherein said other feed roller is adjustably removable with respect to said fixed feed roller so as to increase the distance therebetween to match sheets of increasing thickness while simultaneously moving to an adjusted position in a downstream direction to effect a fulcrum with respect to said fixed roller against which initial bending of a sheet can be achieved by initial adjusting of said bending roller.

References Cited in the file of this patent UNITED STATES PATENTS 220,224 Everson Oct. 7, 1879 1,590,491 Beall June 29, 1926 2,215,111 Tucker Sept. 17, 1940 2,387,688 Spahr Oct. 23, 1945 

